Luo Pan, Zhao Zifu, Yang Fan, Zhang Lai, Li Siyuan, Qiao Ying, Zhang Liangxinyi, Yang Mingchun, Zhou Xiaotong, Zhao Linlin, Yang Yong, Tang Xingchun, Shi Ce
State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Science, Hubei University, Wuhan, China.
State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China.
Plant Cell Environ. 2025 Jan;48(1):421-434. doi: 10.1111/pce.15158. Epub 2024 Sep 13.
The isolated microspores can be reprogrammed towards embryogenesis via stress treatment during in vitro culture, and produce (doubled) haploid plants as a breeding source of new genetic variability. However, the mechanism underlying the cell fate transition from gametogenesis to embryogenesis remains largely unknown. Here, we report that autophagy plays a key role in cell fate transition for microspore embryogenesis (referred to as androgenesis) in Nicotiana tabacum. Immunofluorescence and transmission electronic microscopy detection unveiled that autophagy was triggered in microspores following exposure to inductive stress, and a transient wave of the numerous autophagy-related genes (ATGs) expression occurred before the initiation of microspore embryogenesis. Suppression or promotion of the original autophagy levels could inhibit microspore embryogenesis, indicating that stress-induced autophagic homeostasis is essential for cell fate transition. Furthermore, quantitative proteomics analysis revealed that autophagy might be involved in lignin biosynthesis and chromatin decondensation for promoting reprogramming for androgenesis initiation. Altogether, we reveal an essential role of autophagy in the microspore cell fate transition and androgenesis initiation, providing novel insight for understanding this critical developmental process.
离体小孢子在体外培养过程中可通过胁迫处理重编程为胚胎发生，并产生（双单倍体）单倍体植株，作为新的遗传变异的育种来源。然而，从配子发生到胚胎发生的细胞命运转变的潜在机制仍 largely 未知。在这里，我们报道自噬在烟草小孢子胚胎发生（称为雄核发育）的细胞命运转变中起关键作用。免疫荧光和透射电子显微镜检测表明，在暴露于诱导胁迫后，小孢子中触发了自噬，并且在小孢子胚胎发生开始之前出现了大量自噬相关基因（ATG）表达的瞬时波。抑制或促进原始自噬水平可抑制小孢子胚胎发生，表明胁迫诱导的自噬稳态对于细胞命运转变至关重要。此外，定量蛋白质组学分析表明，自噬可能参与木质素生物合成和染色质去浓缩，以促进雄核发育起始的重编程。总之，我们揭示了自噬在小孢子细胞命运转变和雄核发育起始中的重要作用，为理解这一关键发育过程提供了新的见解。
